The patch titled Subject: maple_tree: fix tracepoint string pointers has been added to the -mm mm-hotfixes-unstable branch. Its filename is maple_tree-fix-tracepoint-string-pointers.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------ From: Martin Kaiser martin@kaiser.cx Subject: maple_tree: fix tracepoint string pointers Date: Thu, 30 Oct 2025 16:55:05 +0100

maple_tree tracepoints contain pointers to function names. Such a pointer is saved when a tracepoint logs an event. There's no guarantee that it's still valid when the event is parsed later and the pointer is dereferenced.

The kernel warns about these unsafe pointers.

event 'ma_read' has unsafe pointer field 'fn' WARNING: kernel/trace/trace.c:3779 at ignore_event+0x1da/0x1e4

Mark the function names as tracepoint_string() to fix the events.

Link: https://lkml.kernel.org/r/20251030155537.87972-1-martin@kaiser.cx Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Martin Kaiser martin@kaiser.cx Cc: Liam Howlett liam.howlett@oracle.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

lib/maple_tree.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-)

--- a/lib/maple_tree.c~maple_tree-fix-tracepoint-string-pointers +++ a/lib/maple_tree.c @@ -64,6 +64,8 @@ #define CREATE_TRACE_POINTS #include <trace/events/maple_tree.h>

+#define TP_FCT tracepoint_string(__func__) + /* * Kernel pointer hashing renders much of the maple tree dump useless as tagged * pointers get hashed to arbitrary values. @@ -2756,7 +2758,7 @@ static inline void mas_rebalance(struct MA_STATE(l_mas, mas->tree, mas->index, mas->last); MA_STATE(r_mas, mas->tree, mas->index, mas->last);

- trace_ma_op(__func__, mas); + trace_ma_op(TP_FCT, mas);

/* * Rebalancing occurs if a node is insufficient. Data is rebalanced @@ -2997,7 +2999,7 @@ static void mas_split(struct ma_state *m MA_STATE(prev_l_mas, mas->tree, mas->index, mas->last); MA_STATE(prev_r_mas, mas->tree, mas->index, mas->last);

- trace_ma_op(__func__, mas); + trace_ma_op(TP_FCT, mas);

mast.l = &l_mas; mast.r = &r_mas; @@ -3172,7 +3174,7 @@ static bool mas_is_span_wr(struct ma_wr_ return false; }

- trace_ma_write(__func__, wr_mas->mas, wr_mas->r_max, entry); + trace_ma_write(TP_FCT, wr_mas->mas, wr_mas->r_max, entry); return true; }

@@ -3416,7 +3418,7 @@ static noinline void mas_wr_spanning_sto * of data may happen. */ mas = wr_mas->mas; - trace_ma_op(__func__, mas); + trace_ma_op(TP_FCT, mas);

if (unlikely(!mas->index && mas->last == ULONG_MAX)) return mas_new_root(mas, wr_mas->entry); @@ -3552,7 +3554,7 @@ done: } else { memcpy(wr_mas->node, newnode, sizeof(struct maple_node)); } - trace_ma_write(__func__, mas, 0, wr_mas->entry); + trace_ma_write(TP_FCT, mas, 0, wr_mas->entry); mas_update_gap(mas); mas->end = new_end; return; @@ -3596,7 +3598,7 @@ static inline void mas_wr_slot_store(str mas->offset++; /* Keep mas accurate. */ }

- trace_ma_write(__func__, mas, 0, wr_mas->entry); + trace_ma_write(TP_FCT, mas, 0, wr_mas->entry); /* * Only update gap when the new entry is empty or there is an empty * entry in the original two ranges. @@ -3717,7 +3719,7 @@ static inline void mas_wr_append(struct mas_update_gap(mas);

mas->end = new_end; - trace_ma_write(__func__, mas, new_end, wr_mas->entry); + trace_ma_write(TP_FCT, mas, new_end, wr_mas->entry); return; }

@@ -3731,7 +3733,7 @@ static void mas_wr_bnode(struct ma_wr_st { struct maple_big_node b_node;

- trace_ma_write(__func__, wr_mas->mas, 0, wr_mas->entry); + trace_ma_write(TP_FCT, wr_mas->mas, 0, wr_mas->entry); memset(&b_node, 0, sizeof(struct maple_big_node)); mas_store_b_node(wr_mas, &b_node, wr_mas->offset_end); mas_commit_b_node(wr_mas, &b_node); @@ -5062,7 +5064,7 @@ void *mas_store(struct ma_state *mas, vo { MA_WR_STATE(wr_mas, mas, entry);

- trace_ma_write(__func__, mas, 0, entry); + trace_ma_write(TP_FCT, mas, 0, entry); #ifdef CONFIG_DEBUG_MAPLE_TREE if (MAS_WARN_ON(mas, mas->index > mas->last)) pr_err("Error %lX > %lX " PTR_FMT "\n", mas->index, mas->last, @@ -5163,7 +5165,7 @@ void mas_store_prealloc(struct ma_state }

store: - trace_ma_write(__func__, mas, 0, entry); + trace_ma_write(TP_FCT, mas, 0, entry); mas_wr_store_entry(&wr_mas); MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas)); mas_destroy(mas); @@ -5882,7 +5884,7 @@ void *mtree_load(struct maple_tree *mt, MA_STATE(mas, mt, index, index); void *entry;

- trace_ma_read(__func__, &mas); + trace_ma_read(TP_FCT, &mas); rcu_read_lock(); retry: entry = mas_start(&mas); @@ -5925,7 +5927,7 @@ int mtree_store_range(struct maple_tree MA_STATE(mas, mt, index, last); int ret = 0;

- trace_ma_write(__func__, &mas, 0, entry); + trace_ma_write(TP_FCT, &mas, 0, entry); if (WARN_ON_ONCE(xa_is_advanced(entry))) return -EINVAL;

@@ -6148,7 +6150,7 @@ void *mtree_erase(struct maple_tree *mt, void *entry = NULL;

MA_STATE(mas, mt, index, index); - trace_ma_op(__func__, &mas); + trace_ma_op(TP_FCT, &mas);

mtree_lock(mt); entry = mas_erase(&mas); @@ -6485,7 +6487,7 @@ void *mt_find(struct maple_tree *mt, uns unsigned long copy = *index; #endif

- trace_ma_read(__func__, &mas); + trace_ma_read(TP_FCT, &mas);

if ((*index) > max) return NULL; _

Patches currently in -mm which might be from martin@kaiser.cx are

maple_tree-fix-tracepoint-string-pointers.patch